Messages in this thread | | | Date | Sun, 05 Aug 2007 18:34:08 +0400 | From | Sergei Shtylyov <> | Subject | Re: libata git tree, mbox queue status and contents |
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Alan Cox wrote:
>>* Alan: IORDY handling -- upstream whenever Alan is happy
> I'm happy with it from testing. Just a little worried about it going > upstream mid -rc as it could have a weird side effect somewhere. I've > verified an original pre ATA IDE drive with it too now 8)
>>* Alan: ACPI checks for 80wire cable -- upstream whenever Alan is happy
> Happy
>>* Albert: irq_on/off. Really need to give this some thought. Not sure >>I like where this model is going. Polling and twiddling irq on/off >>should be kept to a minimum, because it's sorta an admission that the >>host state machine has broken down, and we need to bandaid. Its a >>bandaid not a root-cause solution.
> I think of it more as an admission that the IDE design is lacking in a > few areas. No suprise as its an emulation of a 15 year old interface that > was normally used polled.
Hehe, note that even host polling has always been racy the way ATA spec. described it: there was noting said about the period whithin which the device should assert INTRQ after clearing BSY (and the interrupt-pending state wasn't clearly specified also), so there's a possibility for the fast host to *not* clear interrupt pending by reading the status reg. with BSY=0 but before the devie enters interrupt-pending state, and thus possibly stalling the further transfer.
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